Elektrishun
Ultra Member
I have some devices that are designed to run off of a nominal 9V DC power supply. The type of devices that need the 9V will perform better on a battery source.
The 2 basic battery requirements I was looking for:
- long life battery relative to the power demand (devices have small power demands).
- rechargeable
Standard rechargeable 9V batteries, even two in parallel, didn't have the greatest life for what I wanted. After considering some options I recalled seeing the occasional Makita 9.6V drill and charger combo for sale. I began watching for a drill/battery with charger that looked and sounded like it was well cared for and CHEAP. Found it.
Charged the battery up, put it in the drill, clamped the trigger to run it, and timed how long it ran. Gave the motor a brief rest about every 5-10 mins. Ran for at least 35 minutes total time. Not under load but good enough for my needs.
Next, came up with a design and put it all together. Here's the result without the final polish:
Little circuit board off to the side should OPEN the circuit at about 8V but needs to be tested. I plan on using the old Makita metal case to store this power supply along with the charger.
Roughly 10.54V when fully charged. Devices have their own voltage regulation and can tolerate the range that this power source will provide.
Now, I will need to keep my eyes open for more of these vanishing batteries.🙂
The 2 basic battery requirements I was looking for:
- long life battery relative to the power demand (devices have small power demands).
- rechargeable
Standard rechargeable 9V batteries, even two in parallel, didn't have the greatest life for what I wanted. After considering some options I recalled seeing the occasional Makita 9.6V drill and charger combo for sale. I began watching for a drill/battery with charger that looked and sounded like it was well cared for and CHEAP. Found it.
Charged the battery up, put it in the drill, clamped the trigger to run it, and timed how long it ran. Gave the motor a brief rest about every 5-10 mins. Ran for at least 35 minutes total time. Not under load but good enough for my needs.
Next, came up with a design and put it all together. Here's the result without the final polish:
Little circuit board off to the side should OPEN the circuit at about 8V but needs to be tested. I plan on using the old Makita metal case to store this power supply along with the charger.
Roughly 10.54V when fully charged. Devices have their own voltage regulation and can tolerate the range that this power source will provide.
Now, I will need to keep my eyes open for more of these vanishing batteries.🙂